Don't EVER EVER EVER apologize for being in a cover band. EVER.
There's nothing wrong with it. The whole "originals vs. covers" argument is all elitist bullsh*t, and has no place in music.
My band (Scream), is a cover/tribute band. We pay homage to the era of 80's metal, by performing songs from bands like AC/DC, Aerosmith, KISS, Def Leppard, Rhino Bucket, Jetboy, Dokken, Warrant, and many more. There's nothing wrong with it, and at the end of the night, I'm still getting paid to play drums. So don't ever apologize for playing whatever you play.
Originals, covers, it's all good, as long as it's all music. :wink: